core

### Updating Nominals from CAD

You can update the nominals of features in the Edit window based on an imported CAD file. This makes it possible to easily update your features' nominal (or theoretical) values to match the nominals of the CAD model. This is useful in these situations:

- You have already measured features without any CAD, but you now have CAD, and want to update your features' nominals.

- You want to update your features' nominals to match an updated CAD model.

To update your features' nominals from the CAD:

1. Select File | Import to import the CAD model you want to use. For more information on how to import a model, see "Importing a CAD file" in the "Using Advanced File Options" chapter.

2. Select Operation | Features | Update Nominals from CAD and choose one of these sub-menu items:

All - Updates all the features' nominals in the measurement routine.

Current - Updates only the selected feature's nominals.

The status bar shows the operation results as it runs.

How it Works

This operation uses the Find Noms tolerance located on the General tab of the Setup Options dialog box (Edit | Preferences | Setup). For information on the Find Noms tolerance, see "Other Edit Boxes for the General tab" topic.

This list provides information about how this operation updates the nominals for specific features:

- Point - PC-DMIS uses the XYZ and IJK of the point feature to draw an imaginary line that pierces the CAD model. It updates the nominal values to match the closest intersection to the original XYZ with the CAD model.

- Edge Point, Angle Point, Corner Point - PC-DMIS looks on the CAD model for the nearest feature of that type. The XYZ value must lie within the Find Noms tolerance of the original feature. It then updates the nominal values to match the CAD model.

- Plane - PC-DMIS projects the plane's XYZ onto the CAD model's closest planar surface. The XYZ must lie within the Find Noms tolerance of the original feature. It then updates the nominal values to match the CAD model.

- Circle, Ellipse, Cylinder, Cone, Polygon, Sphere - PC-DMIS looks on the CAD model for the nearest feature of that type. The XYZ and diameter must each lie within the Find Noms tolerance of the original feature. Cylinder and Cone also have a length value that must also lie within the Find Noms tolerance. It then updates the nominal values to match the CAD model.

- Square Slot, Notch Slot, Round Slot, Flush & Gap - PC-DMIS looks on the CAD model for the nearest feature of that type. The XYZ as well as the length and width of the sides must each lie within the Find Noms tolerance of the original feature. It then updates the nominal values to match the CAD model.

- Polygon - PC-DMIS looks on the CAD model for the nearest feature of that type. The XYZ and the diameter must each lie within the Find Noms tolerance of the original feature. The feature on the CAD must have the same number of sides as the original feature. It then updates the nominal values to match the CAD model.

- Line - PC-DMIS projects the line's start and end points of the original feature onto the CAD model. Both points must lie within the Find Noms tolerance. It then updates the nominal values to match the CAD model.

- All other feature types - PC-DMIS locates all the features' hits, and projects each hit onto the CAD model to find the nearest XYZ point on the model. The XYZ of each projected point must lie within the Find Noms tolerance of the original hit.